src/lttng-syscalls.c

   1 /* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
   2  *
   3  * lttng-syscalls.c
   4  *
   5  * LTTng syscall probes.
   6  *
   7  * Copyright (C) 2010-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/slab.h>
  12 #include <linux/compat.h>
  13 #include <linux/err.h>
  14 #include <linux/bitmap.h>
  15 #include <linux/in.h>
  16 #include <linux/in6.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/stringify.h>
  19 #include <linux/file.h>
  20 #include <linux/anon_inodes.h>
  21 #include <linux/fcntl.h>
  22 #include <linux/mman.h>
  23 #include <asm/ptrace.h>
  24 #include <asm/syscall.h>
  25
  26 #include <lttng/bitfield.h>
  27 #include <wrapper/tracepoint.h>
  28 #include <wrapper/file.h>
  29 #include <wrapper/rcu.h>
  30 #include <wrapper/syscall.h>
  31 #include <lttng/events.h>
  32 #include <lttng/events-internal.h>
  33 #include <lttng/utils.h>
  34
  35 #include "lttng-syscalls.h"
  36
  37 #ifndef CONFIG_COMPAT
  38 # ifndef is_compat_task
  39 #  define is_compat_task()      (0)
  40 # endif
  41 #endif
  42
  43 /* in_compat_syscall appears in kernel 4.6. */
  44 #ifndef in_compat_syscall
  45  #define in_compat_syscall()    is_compat_task()
  46 #endif
  47
  48 enum sc_type {
  49         SC_TYPE_ENTRY,
  50         SC_TYPE_EXIT,
  51         SC_TYPE_COMPAT_ENTRY,
  52         SC_TYPE_COMPAT_EXIT,
  53 };
  54
  55 #define SYSCALL_ENTRY_TOK               syscall_entry_
  56 #define COMPAT_SYSCALL_ENTRY_TOK        compat_syscall_entry_
  57 #define SYSCALL_EXIT_TOK                syscall_exit_
  58 #define COMPAT_SYSCALL_EXIT_TOK         compat_syscall_exit_
  59
  60 #define SYSCALL_ENTRY_STR               __stringify(SYSCALL_ENTRY_TOK)
  61 #define COMPAT_SYSCALL_ENTRY_STR        __stringify(COMPAT_SYSCALL_ENTRY_TOK)
  62 #define SYSCALL_EXIT_STR                __stringify(SYSCALL_EXIT_TOK)
  63 #define COMPAT_SYSCALL_EXIT_STR         __stringify(COMPAT_SYSCALL_EXIT_TOK)
  64
  65 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id);
  66 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret);
  67
  68 /*
  69  * Forward declarations for old kernels.
  70  */
  71 struct mmsghdr;
  72 struct rlimit64;
  73 struct oldold_utsname;
  74 struct old_utsname;
  75 struct sel_arg_struct;
  76 struct mmap_arg_struct;
  77 struct file_handle;
  78 struct user_msghdr;
  79
  80 /*
  81  * Forward declaration for kernels >= 5.6
  82  */
  83 struct timex;
  84 struct timeval;
  85 struct itimerval;
  86 struct itimerspec;
  87
  88 #if (LTTNG_LINUX_VERSION_CODE >= LTTNG_KERNEL_VERSION(5,6,0))
  89 typedef __kernel_old_time_t time_t;
  90 #endif
  91
  92 #ifdef IA32_NR_syscalls
  93 #define NR_compat_syscalls IA32_NR_syscalls
  94 #else
  95 #define NR_compat_syscalls NR_syscalls
  96 #endif
  97
  98 /*
  99  * Create LTTng tracepoint probes.
 100  */
 101 #define LTTNG_PACKAGE_BUILD
 102 #define CREATE_TRACE_POINTS
 103 #define TP_MODULE_NOINIT
 104 #define TRACE_INCLUDE_PATH instrumentation/syscalls/headers
 105
 106 #define PARAMS(args...) args
 107
 108 /* Handle unknown syscalls */
 109 #undef TRACE_SYSTEM
 110 #define TRACE_SYSTEM syscalls_unknown
 111 #include <instrumentation/syscalls/headers/syscalls_unknown.h>
 112 #undef TRACE_SYSTEM
 113
 114 #undef TP_PROBE_CB
 115
 116 extern const struct trace_syscall_table sc_table;
 117 extern const struct trace_syscall_table compat_sc_table;
 118
 119 /* Event syscall exit table */
 120 extern const struct trace_syscall_table sc_exit_table;
 121 extern const struct trace_syscall_table compat_sc_exit_table;
 122
 123
 124 #undef SC_EXIT
 125
 126 #undef CREATE_SYSCALL_TABLE
 127
 128 struct lttng_syscall_filter {
 129         DECLARE_BITMAP(sc_entry, NR_syscalls);
 130         DECLARE_BITMAP(sc_exit, NR_syscalls);
 131         DECLARE_BITMAP(sc_compat_entry, NR_compat_syscalls);
 132         DECLARE_BITMAP(sc_compat_exit, NR_compat_syscalls);
 133 };
 134
 135 static
 136 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler);
 137
 138 static void syscall_entry_event_unknown(struct hlist_head *unknown_action_list_head,
 139         struct pt_regs *regs, long id)
 140 {
 141         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 142         struct lttng_kernel_event_common_private *event_priv;
 143
 144         lttng_syscall_get_arguments(current, regs, args);
 145         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 146                 if (unlikely(in_compat_syscall()))
 147                         __event_probe__compat_syscall_entry_unknown(event_priv->pub, id, args);
 148                 else
 149                         __event_probe__syscall_entry_unknown(event_priv->pub, id, args);
 150         }
 151 }
 152
 153 static __always_inline
 154 void syscall_entry_event_call_func(struct hlist_head *action_list,
 155                 void *func, unsigned int nrargs,
 156                 struct pt_regs *regs)
 157 {
 158         struct lttng_kernel_event_common_private *event_priv;
 159
 160         switch (nrargs) {
 161         case 0:
 162         {
 163                 void (*fptr)(void *__data) = func;
 164
 165                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 166                         fptr(event_priv->pub);
 167                 break;
 168         }
 169         case 1:
 170         {
 171                 void (*fptr)(void *__data, unsigned long arg0) = func;
 172                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 173
 174                 lttng_syscall_get_arguments(current, regs, args);
 175                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 176                         fptr(event_priv->pub, args[0]);
 177                 break;
 178         }
 179         case 2:
 180         {
 181                 void (*fptr)(void *__data,
 182                         unsigned long arg0,
 183                         unsigned long arg1) = func;
 184                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 185
 186                 lttng_syscall_get_arguments(current, regs, args);
 187                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 188                         fptr(event_priv->pub, args[0], args[1]);
 189                 break;
 190         }
 191         case 3:
 192         {
 193                 void (*fptr)(void *__data,
 194                         unsigned long arg0,
 195                         unsigned long arg1,
 196                         unsigned long arg2) = func;
 197                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 198
 199                 lttng_syscall_get_arguments(current, regs, args);
 200                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 201                         fptr(event_priv->pub, args[0], args[1], args[2]);
 202                 break;
 203         }
 204         case 4:
 205         {
 206                 void (*fptr)(void *__data,
 207                         unsigned long arg0,
 208                         unsigned long arg1,
 209                         unsigned long arg2,
 210                         unsigned long arg3) = func;
 211                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 212
 213                 lttng_syscall_get_arguments(current, regs, args);
 214                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 215                         fptr(event_priv->pub, args[0], args[1], args[2], args[3]);
 216                 break;
 217         }
 218         case 5:
 219         {
 220                 void (*fptr)(void *__data,
 221                         unsigned long arg0,
 222                         unsigned long arg1,
 223                         unsigned long arg2,
 224                         unsigned long arg3,
 225                         unsigned long arg4) = func;
 226                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 227
 228                 lttng_syscall_get_arguments(current, regs, args);
 229                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 230                         fptr(event_priv->pub, args[0], args[1], args[2], args[3], args[4]);
 231                 break;
 232         }
 233         case 6:
 234         {
 235                 void (*fptr)(void *__data,
 236                         unsigned long arg0,
 237                         unsigned long arg1,
 238                         unsigned long arg2,
 239                         unsigned long arg3,
 240                         unsigned long arg4,
 241                         unsigned long arg5) = func;
 242                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 243
 244                 lttng_syscall_get_arguments(current, regs, args);
 245                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 246                         fptr(event_priv->pub, args[0], args[1], args[2],
 247                              args[3], args[4], args[5]);
 248                 break;
 249         }
 250         default:
 251                 break;
 252         }
 253 }
 254
 255 void syscall_entry_event_probe(void *__data, struct pt_regs *regs, long id)
 256 {
 257         struct lttng_kernel_syscall_table *syscall_table = __data;
 258         struct hlist_head *action_list, *unknown_action_list;
 259         const struct trace_syscall_entry *table, *entry;
 260         size_t table_len;
 261
 262         if (unlikely(in_compat_syscall())) {
 263                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 264
 265                 if (id < 0 || id >= NR_compat_syscalls
 266                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_compat_entry))) {
 267                         /* System call filtered out. */
 268                         return;
 269                 }
 270                 table = compat_sc_table.table;
 271                 table_len = compat_sc_table.len;
 272                 unknown_action_list = &syscall_table->compat_unknown_syscall_dispatch;
 273         } else {
 274                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 275
 276                 if (id < 0 || id >= NR_syscalls
 277                         || (!READ_ONCE(syscall_table->syscall_all_entry) && !test_bit(id, filter->sc_entry))) {
 278                         /* System call filtered out. */
 279                         return;
 280                 }
 281                 table = sc_table.table;
 282                 table_len = sc_table.len;
 283                 unknown_action_list = &syscall_table->unknown_syscall_dispatch;
 284         }
 285         if (unlikely(id < 0 || id >= table_len)) {
 286                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 287                 return;
 288         }
 289
 290         entry = &table[id];
 291         if (!entry->event_func) {
 292                 syscall_entry_event_unknown(unknown_action_list, regs, id);
 293                 return;
 294         }
 295
 296         if (unlikely(in_compat_syscall())) {
 297                 action_list = &syscall_table->compat_syscall_dispatch[id];
 298         } else {
 299                 action_list = &syscall_table->syscall_dispatch[id];
 300         }
 301         if (unlikely(hlist_empty(action_list)))
 302                 return;
 303
 304         syscall_entry_event_call_func(action_list, entry->event_func, entry->nrargs, regs);
 305 }
 306
 307 static void syscall_exit_event_unknown(struct hlist_head *unknown_action_list_head,
 308         struct pt_regs *regs, long id, long ret)
 309 {
 310         unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 311         struct lttng_kernel_event_common_private *event_priv;
 312
 313         lttng_syscall_get_arguments(current, regs, args);
 314         lttng_hlist_for_each_entry_rcu(event_priv, unknown_action_list_head, u.syscall.node) {
 315                 if (unlikely(in_compat_syscall()))
 316                         __event_probe__compat_syscall_exit_unknown(event_priv->pub, id, ret,
 317                                 args);
 318                 else
 319                         __event_probe__syscall_exit_unknown(event_priv->pub, id, ret, args);
 320         }
 321 }
 322
 323 static __always_inline
 324 void syscall_exit_event_call_func(struct hlist_head *action_list,
 325                 void *func, unsigned int nrargs,
 326                 struct pt_regs *regs, long ret)
 327 {
 328         struct lttng_kernel_event_common_private *event_priv;
 329
 330         switch (nrargs) {
 331         case 0:
 332         {
 333                 void (*fptr)(void *__data, long ret) = func;
 334
 335                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 336                         fptr(event_priv->pub, ret);
 337                 break;
 338         }
 339         case 1:
 340         {
 341                 void (*fptr)(void *__data,
 342                         long ret,
 343                         unsigned long arg0) = func;
 344                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 345
 346                 lttng_syscall_get_arguments(current, regs, args);
 347                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 348                         fptr(event_priv->pub, ret, args[0]);
 349                 break;
 350         }
 351         case 2:
 352         {
 353                 void (*fptr)(void *__data,
 354                         long ret,
 355                         unsigned long arg0,
 356                         unsigned long arg1) = func;
 357                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 358
 359                 lttng_syscall_get_arguments(current, regs, args);
 360                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 361                         fptr(event_priv->pub, ret, args[0], args[1]);
 362                 break;
 363         }
 364         case 3:
 365         {
 366                 void (*fptr)(void *__data,
 367                         long ret,
 368                         unsigned long arg0,
 369                         unsigned long arg1,
 370                         unsigned long arg2) = func;
 371                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 372
 373                 lttng_syscall_get_arguments(current, regs, args);
 374                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 375                         fptr(event_priv->pub, ret, args[0], args[1], args[2]);
 376                 break;
 377         }
 378         case 4:
 379         {
 380                 void (*fptr)(void *__data,
 381                         long ret,
 382                         unsigned long arg0,
 383                         unsigned long arg1,
 384                         unsigned long arg2,
 385                         unsigned long arg3) = func;
 386                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 387
 388                 lttng_syscall_get_arguments(current, regs, args);
 389                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 390                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3]);
 391                 break;
 392         }
 393         case 5:
 394         {
 395                 void (*fptr)(void *__data,
 396                         long ret,
 397                         unsigned long arg0,
 398                         unsigned long arg1,
 399                         unsigned long arg2,
 400                         unsigned long arg3,
 401                         unsigned long arg4) = func;
 402                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 403
 404                 lttng_syscall_get_arguments(current, regs, args);
 405                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 406                         fptr(event_priv->pub, ret, args[0], args[1], args[2], args[3], args[4]);
 407                 break;
 408         }
 409         case 6:
 410         {
 411                 void (*fptr)(void *__data,
 412                         long ret,
 413                         unsigned long arg0,
 414                         unsigned long arg1,
 415                         unsigned long arg2,
 416                         unsigned long arg3,
 417                         unsigned long arg4,
 418                         unsigned long arg5) = func;
 419                 unsigned long args[LTTNG_SYSCALL_NR_ARGS];
 420
 421                 lttng_syscall_get_arguments(current, regs, args);
 422                 lttng_hlist_for_each_entry_rcu(event_priv, action_list, u.syscall.node)
 423                         fptr(event_priv->pub, ret, args[0], args[1], args[2],
 424                              args[3], args[4], args[5]);
 425                 break;
 426         }
 427         default:
 428                 break;
 429         }
 430 }
 431
 432 void syscall_exit_event_probe(void *__data, struct pt_regs *regs, long ret)
 433 {
 434         struct lttng_kernel_syscall_table *syscall_table = __data;
 435         struct hlist_head *action_list, *unknown_action_list;
 436         const struct trace_syscall_entry *table, *entry;
 437         size_t table_len;
 438         long id;
 439
 440         id = syscall_get_nr(current, regs);
 441
 442         if (unlikely(in_compat_syscall())) {
 443                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 444
 445                 if (id < 0 || id >= NR_compat_syscalls
 446                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_compat_exit))) {
 447                         /* System call filtered out. */
 448                         return;
 449                 }
 450                 table = compat_sc_exit_table.table;
 451                 table_len = compat_sc_exit_table.len;
 452                 unknown_action_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 453         } else {
 454                 struct lttng_syscall_filter *filter = syscall_table->sc_filter;
 455
 456                 if (id < 0 || id >= NR_syscalls
 457                         || (!READ_ONCE(syscall_table->syscall_all_exit) && !test_bit(id, filter->sc_exit))) {
 458                         /* System call filtered out. */
 459                         return;
 460                 }
 461                 table = sc_exit_table.table;
 462                 table_len = sc_exit_table.len;
 463                 unknown_action_list = &syscall_table->unknown_syscall_exit_dispatch;
 464         }
 465         if (unlikely(id < 0 || id >= table_len)) {
 466                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 467                 return;
 468         }
 469
 470         entry = &table[id];
 471         if (!entry->event_func) {
 472                 syscall_exit_event_unknown(unknown_action_list, regs, id, ret);
 473                 return;
 474         }
 475
 476         if (unlikely(in_compat_syscall())) {
 477                 action_list = &syscall_table->compat_syscall_exit_dispatch[id];
 478         } else {
 479                 action_list = &syscall_table->syscall_exit_dispatch[id];
 480         }
 481         if (unlikely(hlist_empty(action_list)))
 482                 return;
 483
 484         syscall_exit_event_call_func(action_list, entry->event_func, entry->nrargs,
 485                                regs, ret);
 486 }
 487
 488 static
 489 struct lttng_kernel_syscall_table *get_syscall_table_from_enabler(struct lttng_event_enabler_common *event_enabler)
 490 {
 491         switch (event_enabler->enabler_type) {
 492         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 493         {
 494                 struct lttng_event_recorder_enabler *event_recorder_enabler =
 495                         container_of(event_enabler, struct lttng_event_recorder_enabler, parent);
 496                 return &event_recorder_enabler->chan->priv->parent.syscall_table;
 497         }
 498         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 499         {
 500                 struct lttng_event_notifier_enabler *event_notifier_enabler =
 501                         container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 502                 return &event_notifier_enabler->group->syscall_table;
 503         }
 504         default:
 505                 return NULL;
 506         }
 507 }
 508
 509 static
 510 struct lttng_kernel_syscall_table *get_syscall_table_from_event(struct lttng_kernel_event_common *event)
 511 {
 512         switch (event->type) {
 513         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
 514         {
 515                 struct lttng_kernel_event_recorder *event_recorder =
 516                         container_of(event, struct lttng_kernel_event_recorder, parent);
 517                 return &event_recorder->chan->priv->parent.syscall_table;
 518         }
 519         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
 520         {
 521                 struct lttng_kernel_event_notifier *event_notifier =
 522                         container_of(event, struct lttng_kernel_event_notifier, parent);
 523                 return &event_notifier->priv->group->syscall_table;
 524         }
 525         default:
 526                 return NULL;
 527         }
 528 }
 529
 530 static
 531 void lttng_syscall_event_enabler_create_event(struct lttng_event_enabler_common *syscall_event_enabler,
 532                 const struct lttng_kernel_event_desc *desc, struct hlist_head *dispatch_table,
 533                 enum sc_type type, unsigned int syscall_nr)
 534 {
 535         struct lttng_kernel_event_common *event;
 536
 537         switch (syscall_event_enabler->enabler_type) {
 538         case LTTNG_EVENT_ENABLER_TYPE_RECORDER:
 539         {
 540                 struct lttng_event_recorder_enabler *syscall_event_recorder_enabler =
 541                         container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 542                 struct lttng_event_recorder_enabler *event_recorder_enabler;
 543                 struct lttng_kernel_abi_event ev;
 544
 545                 /* We need to create an event for this syscall/enabler. */
 546                 memset(&ev, 0, sizeof(ev));
 547                 switch (type) {
 548                 case SC_TYPE_ENTRY:
 549                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 550                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 551                         break;
 552                 case SC_TYPE_EXIT:
 553                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 554                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 555                         break;
 556                 case SC_TYPE_COMPAT_ENTRY:
 557                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 558                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 559                         break;
 560                 case SC_TYPE_COMPAT_EXIT:
 561                         ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 562                         ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 563                         break;
 564                 }
 565                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1);
 566                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 567                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 568                 event_recorder_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev,
 569                                 syscall_event_recorder_enabler->chan);
 570                 WARN_ON_ONCE(!event_recorder_enabler);
 571                 if (!event_recorder_enabler)
 572                         return;
 573                 event = _lttng_kernel_event_create(&event_recorder_enabler->parent, desc);
 574                 WARN_ON_ONCE(!event || IS_ERR(event));
 575                 lttng_event_enabler_destroy(&event_recorder_enabler->parent);
 576                 if (!event || IS_ERR(event)) {
 577                         printk(KERN_INFO "Unable to create event recorder %s\n", desc->event_name);
 578                         return;
 579                 }
 580                 hlist_add_head(&event->priv->u.syscall.node, &dispatch_table[syscall_nr]);
 581                 break;
 582         }
 583         case LTTNG_EVENT_ENABLER_TYPE_NOTIFIER:
 584         {
 585                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler =
 586                         container_of(syscall_event_enabler, struct lttng_event_notifier_enabler, parent);
 587                 struct lttng_event_notifier_enabler *event_notifier_enabler;
 588                 struct lttng_kernel_abi_event_notifier event_notifier_param;
 589                 uint64_t user_token = syscall_event_enabler->user_token;
 590                 uint64_t error_counter_index = syscall_event_notifier_enabler->error_counter_index;
 591
 592                 memset(&event_notifier_param, 0, sizeof(event_notifier_param));
 593                 switch (type) {
 594                 case SC_TYPE_ENTRY:
 595                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 596                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 597                         break;
 598                 case SC_TYPE_EXIT:
 599                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 600                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 601                         break;
 602                 case SC_TYPE_COMPAT_ENTRY:
 603                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 604                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 605                         break;
 606                 case SC_TYPE_COMPAT_EXIT:
 607                         event_notifier_param.event.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 608                         event_notifier_param.event.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 609                         break;
 610                 }
 611                 strncat(event_notifier_param.event.name, desc->event_name,
 612                         LTTNG_KERNEL_ABI_SYM_NAME_LEN - strlen(event_notifier_param.event.name) - 1);
 613                 event_notifier_param.event.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 614                 event_notifier_param.event.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 615                 event_notifier_param.event.token = user_token;
 616                 event_notifier_param.error_counter_index = error_counter_index;
 617
 618                 event_notifier_enabler = lttng_event_notifier_enabler_create(LTTNG_ENABLER_FORMAT_NAME,
 619                                 &event_notifier_param, syscall_event_notifier_enabler->group);
 620                 WARN_ON_ONCE(!event_notifier_enabler);
 621                 event = _lttng_kernel_event_create(&event_notifier_enabler->parent, desc);
 622                 WARN_ON_ONCE(!event || IS_ERR(event));
 623                 lttng_event_enabler_destroy(&event_notifier_enabler->parent);
 624                 if (!event || IS_ERR(event)) {
 625                         printk(KERN_INFO "Unable to create event notifier %s\n", desc->event_name);
 626                         return;
 627                 }
 628                 event->priv->u.syscall.syscall_id = syscall_nr;
 629                 break;
 630         }
 631         default:
 632                 break;
 633         }
 634 }
 635
 636 /*
 637  * noinline to diminish caller stack size.
 638  * Should be called with sessions lock held.
 639  */
 640 static
 641 int lttng_create_syscall_event_if_missing(const struct trace_syscall_entry *table, size_t table_len,
 642         struct hlist_head *dispatch_table, struct lttng_event_recorder_enabler *syscall_event_enabler,
 643         enum sc_type type)
 644 {
 645         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_enabler->parent);
 646         unsigned int i;
 647
 648         /* Allocate events for each syscall matching enabler, insert into table */
 649         for (i = 0; i < table_len; i++) {
 650                 const struct lttng_kernel_event_desc *desc = table[i].desc;
 651                 struct lttng_kernel_event_common_private *event_priv;
 652                 struct hlist_head *head;
 653                 bool found = false;
 654
 655                 if (!desc) {
 656                         /* Unknown syscall */
 657                         continue;
 658                 }
 659                 if (!lttng_desc_match_enabler(desc,
 660                                 lttng_event_recorder_enabler_as_enabler(syscall_event_enabler)))
 661                         continue;
 662                 /*
 663                  * Check if already created.
 664                  */
 665                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 666                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 667                         if (lttng_event_enabler_desc_match_event(&syscall_event_enabler->parent, desc, event_priv->pub))
 668                                 found = true;
 669                 }
 670                 if (found)
 671                         continue;
 672
 673                 lttng_syscall_event_enabler_create_event(&syscall_event_enabler->parent, desc, dispatch_table, type, i);
 674         }
 675         return 0;
 676 }
 677
 678 static
 679 int lttng_syscalls_populate_events(struct lttng_event_enabler_common *syscall_event_enabler)
 680 {
 681         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 682         struct lttng_event_recorder_enabler *event_recorder_enabler;
 683         struct lttng_kernel_channel_buffer *chan;
 684         struct lttng_kernel_abi_event ev;
 685         int ret;
 686
 687         if (syscall_event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_RECORDER)
 688                 return 0;
 689         event_recorder_enabler = container_of(syscall_event_enabler, struct lttng_event_recorder_enabler, parent);
 690         chan = event_recorder_enabler->chan;
 691
 692         if (hlist_empty(&syscall_table->unknown_syscall_dispatch)) {
 693                 const struct lttng_kernel_event_desc *desc =
 694                         &__event_desc___syscall_entry_unknown;
 695                 struct lttng_kernel_event_common *event;
 696                 struct lttng_event_recorder_enabler *event_enabler;
 697
 698                 memset(&ev, 0, sizeof(ev));
 699                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 700                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 701                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 702                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 703                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 704                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 705                 if (!event_enabler) {
 706                         return -ENOMEM;
 707                 }
 708                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 709                 lttng_event_enabler_destroy(&event_enabler->parent);
 710                 WARN_ON_ONCE(!event);
 711                 if (IS_ERR(event)) {
 712                         return PTR_ERR(event);
 713                 }
 714                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_dispatch);
 715         }
 716
 717         if (hlist_empty(&syscall_table->compat_unknown_syscall_dispatch)) {
 718                 const struct lttng_kernel_event_desc *desc =
 719                         &__event_desc___compat_syscall_entry_unknown;
 720                 struct lttng_kernel_event_common *event;
 721                 struct lttng_event_recorder_enabler *event_enabler;
 722
 723                 memset(&ev, 0, sizeof(ev));
 724                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 725                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 726                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 727                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_ENTRY;
 728                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 729                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 730                 if (!event_enabler) {
 731                         return -ENOMEM;
 732                 }
 733                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 734                 WARN_ON_ONCE(!event);
 735                 lttng_event_enabler_destroy(&event_enabler->parent);
 736                 if (IS_ERR(event)) {
 737                         return PTR_ERR(event);
 738                 }
 739                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_dispatch);
 740         }
 741
 742         if (hlist_empty(&syscall_table->compat_unknown_syscall_exit_dispatch)) {
 743                 const struct lttng_kernel_event_desc *desc =
 744                         &__event_desc___compat_syscall_exit_unknown;
 745                 struct lttng_kernel_event_common *event;
 746                 struct lttng_event_recorder_enabler *event_enabler;
 747
 748                 memset(&ev, 0, sizeof(ev));
 749                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 750                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 751                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 752                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 753                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_COMPAT;
 754                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 755                 if (!event_enabler) {
 756                         return -ENOMEM;
 757                 }
 758                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 759                 WARN_ON_ONCE(!event);
 760                 lttng_event_enabler_destroy(&event_enabler->parent);
 761                 if (IS_ERR(event)) {
 762                         return PTR_ERR(event);
 763                 }
 764                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->compat_unknown_syscall_exit_dispatch);
 765         }
 766
 767         if (hlist_empty(&syscall_table->unknown_syscall_exit_dispatch)) {
 768                 const struct lttng_kernel_event_desc *desc =
 769                         &__event_desc___syscall_exit_unknown;
 770                 struct lttng_kernel_event_common *event;
 771                 struct lttng_event_recorder_enabler *event_enabler;
 772
 773                 memset(&ev, 0, sizeof(ev));
 774                 strncpy(ev.name, desc->event_name, LTTNG_KERNEL_ABI_SYM_NAME_LEN);
 775                 ev.name[LTTNG_KERNEL_ABI_SYM_NAME_LEN - 1] = '\0';
 776                 ev.instrumentation = LTTNG_KERNEL_ABI_SYSCALL;
 777                 ev.u.syscall.entryexit = LTTNG_KERNEL_ABI_SYSCALL_EXIT;
 778                 ev.u.syscall.abi = LTTNG_KERNEL_ABI_SYSCALL_ABI_NATIVE;
 779                 event_enabler = lttng_event_recorder_enabler_create(LTTNG_ENABLER_FORMAT_NAME, &ev, chan);
 780                 if (!event_enabler) {
 781                         return -ENOMEM;
 782                 }
 783                 event = _lttng_kernel_event_create(&event_enabler->parent, desc);
 784                 WARN_ON_ONCE(!event);
 785                 lttng_event_enabler_destroy(&event_enabler->parent);
 786                 if (IS_ERR(event)) {
 787                         return PTR_ERR(event);
 788                 }
 789                 hlist_add_head(&event->priv->u.syscall.node, &syscall_table->unknown_syscall_exit_dispatch);
 790         }
 791
 792         ret = lttng_create_syscall_event_if_missing(sc_table.table, sc_table.len,
 793                         syscall_table->syscall_dispatch, event_recorder_enabler, SC_TYPE_ENTRY);
 794         if (ret)
 795                 return ret;
 796         ret = lttng_create_syscall_event_if_missing(sc_exit_table.table, sc_exit_table.len,
 797                         syscall_table->syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_EXIT);
 798         if (ret)
 799                 return ret;
 800
 801 #ifdef CONFIG_COMPAT
 802         ret = lttng_create_syscall_event_if_missing(compat_sc_table.table, compat_sc_table.len,
 803                         syscall_table->compat_syscall_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_ENTRY);
 804         if (ret)
 805                 return ret;
 806         ret = lttng_create_syscall_event_if_missing(compat_sc_exit_table.table, compat_sc_exit_table.len,
 807                         syscall_table->compat_syscall_exit_dispatch, event_recorder_enabler, SC_TYPE_COMPAT_EXIT);
 808         if (ret)
 809                 return ret;
 810 #endif
 811         return ret;
 812 }
 813
 814 /*
 815  * Should be called with sessions lock held.
 816  */
 817 int lttng_event_enabler_create_syscall_events_if_missing(struct lttng_event_enabler_common *syscall_event_enabler)
 818 {
 819         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(syscall_event_enabler);
 820         int ret;
 821
 822         if (!syscall_table->syscall_dispatch) {
 823                 /* create syscall table mapping syscall to events */
 824                 syscall_table->syscall_dispatch = kzalloc(sizeof(struct hlist_head) * sc_table.len, GFP_KERNEL);
 825                 if (!syscall_table->syscall_dispatch)
 826                         return -ENOMEM;
 827         }
 828         if (!syscall_table->syscall_exit_dispatch) {
 829                 /* create syscall table mapping syscall to events */
 830                 syscall_table->syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * sc_exit_table.len, GFP_KERNEL);
 831                 if (!syscall_table->syscall_exit_dispatch)
 832                         return -ENOMEM;
 833         }
 834
 835
 836 #ifdef CONFIG_COMPAT
 837         if (!syscall_table->compat_syscall_dispatch) {
 838                 /* create syscall table mapping compat syscall to events */
 839                 syscall_table->compat_syscall_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_table.len, GFP_KERNEL);
 840                 if (!syscall_table->compat_syscall_dispatch)
 841                         return -ENOMEM;
 842         }
 843
 844         if (!syscall_table->compat_syscall_exit_dispatch) {
 845                 /* create syscall table mapping compat syscall to events */
 846                 syscall_table->compat_syscall_exit_dispatch = kzalloc(sizeof(struct hlist_head) * compat_sc_exit_table.len, GFP_KERNEL);
 847                 if (!syscall_table->compat_syscall_exit_dispatch)
 848                         return -ENOMEM;
 849         }
 850 #endif
 851         if (!syscall_table->sc_filter) {
 852                 syscall_table->sc_filter = kzalloc(sizeof(struct lttng_syscall_filter),
 853                                 GFP_KERNEL);
 854                 if (!syscall_table->sc_filter)
 855                         return -ENOMEM;
 856         }
 857
 858         ret = lttng_syscalls_populate_events(syscall_event_enabler);
 859         if (ret)
 860                 return ret;
 861
 862         ret = lttng_syscalls_create_matching_event_notifiers(syscall_event_enabler);
 863         if (ret)
 864                 return ret;
 865
 866         if (!syscall_table->sys_enter_registered) {
 867                 ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
 868                                 (void *) syscall_entry_event_probe, syscall_table);
 869                 if (ret)
 870                         return ret;
 871                 syscall_table->sys_enter_registered = 1;
 872         }
 873         if (!syscall_table->sys_exit_registered) {
 874                 ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
 875                                 (void *) syscall_exit_event_probe, syscall_table);
 876                 if (ret) {
 877                         WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
 878                                 (void *) syscall_entry_event_probe, syscall_table));
 879                         return ret;
 880                 }
 881                 syscall_table->sys_exit_registered = 1;
 882         }
 883
 884         return ret;
 885 }
 886
 887 static
 888 void create_unknown_event_notifier(
 889                 struct lttng_event_notifier_enabler *event_notifier_enabler,
 890                 enum sc_type type)
 891 {
 892         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(&event_notifier_enabler->parent);
 893         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&event_notifier_enabler->parent);
 894         struct lttng_kernel_event_common_private *event_priv;
 895         const struct lttng_kernel_event_desc *desc;
 896         struct hlist_head *unknown_dispatch_list;
 897         bool found = false;
 898         struct hlist_head *head;
 899
 900         switch (type) {
 901         case SC_TYPE_ENTRY:
 902                 desc = &__event_desc___syscall_entry_unknown;
 903                 unknown_dispatch_list = &syscall_table->unknown_syscall_dispatch;
 904                 break;
 905         case SC_TYPE_EXIT:
 906                 desc = &__event_desc___syscall_exit_unknown;
 907                 unknown_dispatch_list = &syscall_table->unknown_syscall_exit_dispatch;
 908                 break;
 909         case SC_TYPE_COMPAT_ENTRY:
 910                 desc = &__event_desc___compat_syscall_entry_unknown;
 911                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_dispatch;
 912                 break;
 913         case SC_TYPE_COMPAT_EXIT:
 914                 desc = &__event_desc___compat_syscall_exit_unknown;
 915                 unknown_dispatch_list = &syscall_table->compat_unknown_syscall_exit_dispatch;
 916                 break;
 917         default:
 918                 WARN_ON_ONCE(1);
 919         }
 920
 921         /*
 922          * Check if already created.
 923          */
 924         head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 925         lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 926                 if (lttng_event_enabler_desc_match_event(&event_notifier_enabler->parent, desc, event_priv->pub))
 927                         found = true;
 928         }
 929         if (!found)
 930                 lttng_syscall_event_enabler_create_event(&event_notifier_enabler->parent, desc, unknown_dispatch_list, type, -1U);
 931 }
 932
 933 static
 934 void create_matching_event_notifiers(
 935                 struct lttng_event_notifier_enabler *syscall_event_notifier_enabler,
 936                 const struct trace_syscall_entry *table,
 937                 size_t table_len, enum sc_type type)
 938 {
 939         struct lttng_event_ht *events_ht = lttng_get_event_ht_from_enabler(&syscall_event_notifier_enabler->parent);
 940         const struct lttng_kernel_event_desc *desc;
 941         unsigned int i;
 942
 943         /* iterate over all syscall and create event_notifier that match */
 944         for (i = 0; i < table_len; i++) {
 945                 struct lttng_kernel_event_common_private *event_priv;
 946                 struct hlist_head *head;
 947                 int found = 0;
 948
 949                 desc = table[i].desc;
 950                 if (!desc) {
 951                         /* Unknown syscall */
 952                         continue;
 953                 }
 954
 955                 if (!lttng_desc_match_enabler(desc,
 956                                 lttng_event_notifier_enabler_as_enabler(syscall_event_notifier_enabler)))
 957                         continue;
 958
 959                 /*
 960                  * Check if already created.
 961                  */
 962                 head = utils_borrow_hash_table_bucket(events_ht->table, LTTNG_EVENT_HT_SIZE, desc->event_name);
 963                 lttng_hlist_for_each_entry(event_priv, head, hlist_node) {
 964                         if (lttng_event_enabler_desc_match_event(&syscall_event_notifier_enabler->parent, desc, event_priv->pub))
 965                                 found = 1;
 966                 }
 967                 if (found)
 968                         continue;
 969
 970                 lttng_syscall_event_enabler_create_event(&syscall_event_notifier_enabler->parent, desc, NULL, type, i);
 971         }
 972 }
 973
 974 static
 975 int lttng_syscalls_create_matching_event_notifiers(struct lttng_event_enabler_common *event_enabler)
 976 {
 977         int ret;
 978         enum lttng_kernel_abi_syscall_entryexit entryexit =
 979                         event_enabler->event_param.u.syscall.entryexit;
 980         struct lttng_event_notifier_enabler *event_notifier_enabler;
 981
 982         if (event_enabler->enabler_type != LTTNG_EVENT_ENABLER_TYPE_NOTIFIER)
 983                 return 0;
 984         event_notifier_enabler = container_of(event_enabler, struct lttng_event_notifier_enabler, parent);
 985
 986         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 987                 create_matching_event_notifiers(event_notifier_enabler,
 988                         sc_table.table, sc_table.len, SC_TYPE_ENTRY);
 989                 create_matching_event_notifiers(event_notifier_enabler,
 990                         compat_sc_table.table, compat_sc_table.len,
 991                         SC_TYPE_COMPAT_ENTRY);
 992                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_ENTRY);
 993                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_ENTRY);
 994         }
 995
 996         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT) {
 997                 create_matching_event_notifiers(event_notifier_enabler,
 998                         sc_exit_table.table, sc_exit_table.len,
 999                         SC_TYPE_EXIT);
1000                 create_matching_event_notifiers(event_notifier_enabler,
1001                         compat_sc_exit_table.table, compat_sc_exit_table.len,
1002                         SC_TYPE_COMPAT_EXIT);
1003                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_EXIT);
1004                 create_unknown_event_notifier(event_notifier_enabler, SC_TYPE_COMPAT_EXIT);
1005         }
1006         return ret;
1007 }
1008
1009 int lttng_syscalls_unregister_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1010 {
1011         int ret;
1012
1013         if (!syscall_table->syscall_dispatch)
1014                 return 0;
1015         if (syscall_table->sys_enter_registered) {
1016                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_enter",
1017                                 (void *) syscall_entry_event_probe, syscall_table);
1018                 if (ret)
1019                         return ret;
1020                 syscall_table->sys_enter_registered = 0;
1021         }
1022         if (syscall_table->sys_exit_registered) {
1023                 ret = lttng_wrapper_tracepoint_probe_unregister("sys_exit",
1024                                 (void *) syscall_exit_event_probe, syscall_table);
1025                 if (ret)
1026                         return ret;
1027                 syscall_table->sys_exit_registered = 0;
1028         }
1029         return 0;
1030 }
1031
1032 int lttng_syscalls_destroy_syscall_table(struct lttng_kernel_syscall_table *syscall_table)
1033 {
1034         kfree(syscall_table->syscall_dispatch);
1035         kfree(syscall_table->syscall_exit_dispatch);
1036 #ifdef CONFIG_COMPAT
1037         kfree(syscall_table->compat_syscall_dispatch);
1038         kfree(syscall_table->compat_syscall_exit_dispatch);
1039 #endif
1040         kfree(syscall_table->sc_filter);
1041         return 0;
1042 }
1043
1044 static
1045 int get_syscall_nr(const char *syscall_name)
1046 {
1047         int syscall_nr = -1;
1048         int i;
1049
1050         for (i = 0; i < sc_table.len; i++) {
1051                 const struct trace_syscall_entry *entry;
1052                 const char *it_name;
1053
1054                 entry = &sc_table.table[i];
1055                 if (!entry->desc)
1056                         continue;
1057                 it_name = entry->desc->event_name;
1058                 it_name += strlen(SYSCALL_ENTRY_STR);
1059                 if (!strcmp(syscall_name, it_name)) {
1060                         syscall_nr = i;
1061                         break;
1062                 }
1063         }
1064         return syscall_nr;
1065 }
1066
1067 static
1068 int get_compat_syscall_nr(const char *syscall_name)
1069 {
1070         int syscall_nr = -1;
1071         int i;
1072
1073         for (i = 0; i < compat_sc_table.len; i++) {
1074                 const struct trace_syscall_entry *entry;
1075                 const char *it_name;
1076
1077                 entry = &compat_sc_table.table[i];
1078                 if (!entry->desc)
1079                         continue;
1080                 it_name = entry->desc->event_name;
1081                 it_name += strlen(COMPAT_SYSCALL_ENTRY_STR);
1082                 if (!strcmp(syscall_name, it_name)) {
1083                         syscall_nr = i;
1084                         break;
1085                 }
1086         }
1087         return syscall_nr;
1088 }
1089
1090 static
1091 uint32_t get_sc_tables_len(void)
1092 {
1093         return sc_table.len + compat_sc_table.len;
1094 }
1095
1096 static
1097 const char *get_syscall_name(const char *desc_name,
1098                 enum lttng_syscall_abi abi,
1099                 enum lttng_syscall_entryexit entryexit)
1100 {
1101         size_t prefix_len = 0;
1102
1103
1104         switch (entryexit) {
1105         case LTTNG_SYSCALL_ENTRY:
1106                 switch (abi) {
1107                 case LTTNG_SYSCALL_ABI_NATIVE:
1108                         prefix_len = strlen(SYSCALL_ENTRY_STR);
1109                         break;
1110                 case LTTNG_SYSCALL_ABI_COMPAT:
1111                         prefix_len = strlen(COMPAT_SYSCALL_ENTRY_STR);
1112                         break;
1113                 }
1114                 break;
1115         case LTTNG_SYSCALL_EXIT:
1116                 switch (abi) {
1117                 case LTTNG_SYSCALL_ABI_NATIVE:
1118                         prefix_len = strlen(SYSCALL_EXIT_STR);
1119                         break;
1120                 case LTTNG_SYSCALL_ABI_COMPAT:
1121                         prefix_len = strlen(COMPAT_SYSCALL_EXIT_STR);
1122                         break;
1123                 }
1124                 break;
1125         }
1126         WARN_ON_ONCE(prefix_len == 0);
1127         return desc_name + prefix_len;
1128 }
1129
1130 static
1131 int lttng_syscall_filter_enable(
1132                 struct lttng_syscall_filter *filter,
1133                 const char *desc_name, enum lttng_syscall_abi abi,
1134                 enum lttng_syscall_entryexit entryexit)
1135 {
1136         const char *syscall_name;
1137         unsigned long *bitmap;
1138         int syscall_nr;
1139
1140         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1141
1142         switch (abi) {
1143         case LTTNG_SYSCALL_ABI_NATIVE:
1144                 syscall_nr = get_syscall_nr(syscall_name);
1145                 break;
1146         case LTTNG_SYSCALL_ABI_COMPAT:
1147                 syscall_nr = get_compat_syscall_nr(syscall_name);
1148                 break;
1149         default:
1150                 return -EINVAL;
1151         }
1152         if (syscall_nr < 0)
1153                 return -ENOENT;
1154
1155         switch (entryexit) {
1156         case LTTNG_SYSCALL_ENTRY:
1157                 switch (abi) {
1158                 case LTTNG_SYSCALL_ABI_NATIVE:
1159                         bitmap = filter->sc_entry;
1160                         break;
1161                 case LTTNG_SYSCALL_ABI_COMPAT:
1162                         bitmap = filter->sc_compat_entry;
1163                         break;
1164                 default:
1165                         return -EINVAL;
1166                 }
1167                 break;
1168         case LTTNG_SYSCALL_EXIT:
1169                 switch (abi) {
1170                 case LTTNG_SYSCALL_ABI_NATIVE:
1171                         bitmap = filter->sc_exit;
1172                         break;
1173                 case LTTNG_SYSCALL_ABI_COMPAT:
1174                         bitmap = filter->sc_compat_exit;
1175                         break;
1176                 default:
1177                         return -EINVAL;
1178                 }
1179                 break;
1180         default:
1181                 return -EINVAL;
1182         }
1183         if (test_bit(syscall_nr, bitmap))
1184                 return -EEXIST;
1185         bitmap_set(bitmap, syscall_nr, 1);
1186         return 0;
1187 }
1188
1189 int lttng_syscall_filter_enable_event(struct lttng_kernel_event_common *event)
1190 {
1191         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1192         int ret;
1193
1194         WARN_ON_ONCE(event->priv->instrumentation != LTTNG_KERNEL_ABI_SYSCALL);
1195
1196         ret = lttng_syscall_filter_enable(syscall_table->sc_filter,
1197                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1198                 event->priv->u.syscall.entryexit);
1199         if (ret)
1200                 return ret;
1201
1202         switch (event->type) {
1203         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1204                 break;
1205         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1206         {
1207                 unsigned int syscall_id = event->priv->u.syscall.syscall_id;
1208                 struct hlist_head *dispatch_list;
1209
1210                 switch (event->priv->u.syscall.entryexit) {
1211                 case LTTNG_SYSCALL_ENTRY:
1212                         switch (event->priv->u.syscall.abi) {
1213                         case LTTNG_SYSCALL_ABI_NATIVE:
1214                                 dispatch_list = &syscall_table->syscall_dispatch[syscall_id];
1215                                 break;
1216                         case LTTNG_SYSCALL_ABI_COMPAT:
1217                                 dispatch_list = &syscall_table->compat_syscall_dispatch[syscall_id];
1218                                 break;
1219                         default:
1220                                 ret = -EINVAL;
1221                                 goto end;
1222                         }
1223                         break;
1224                 case LTTNG_SYSCALL_EXIT:
1225                         switch (event->priv->u.syscall.abi) {
1226                         case LTTNG_SYSCALL_ABI_NATIVE:
1227                                 dispatch_list = &syscall_table->syscall_exit_dispatch[syscall_id];
1228                                 break;
1229                         case LTTNG_SYSCALL_ABI_COMPAT:
1230                                 dispatch_list = &syscall_table->compat_syscall_exit_dispatch[syscall_id];
1231                                 break;
1232                         default:
1233                                 ret = -EINVAL;
1234                                 goto end;
1235                         }
1236                         break;
1237                 default:
1238                         ret = -EINVAL;
1239                         goto end;
1240                 }
1241
1242                 hlist_add_head_rcu(&event->priv->u.syscall.node, dispatch_list);
1243                 break;
1244         }
1245         default:
1246                 WARN_ON_ONCE(1);
1247                 return -ENOSYS;
1248         }
1249 end:
1250         return ret;
1251 }
1252
1253 static
1254 int lttng_syscall_filter_disable(struct lttng_syscall_filter *filter,
1255                 const char *desc_name, enum lttng_syscall_abi abi,
1256                 enum lttng_syscall_entryexit entryexit)
1257 {
1258         const char *syscall_name;
1259         unsigned long *bitmap;
1260         int syscall_nr;
1261
1262         syscall_name = get_syscall_name(desc_name, abi, entryexit);
1263
1264         switch (abi) {
1265         case LTTNG_SYSCALL_ABI_NATIVE:
1266                 syscall_nr = get_syscall_nr(syscall_name);
1267                 break;
1268         case LTTNG_SYSCALL_ABI_COMPAT:
1269                 syscall_nr = get_compat_syscall_nr(syscall_name);
1270                 break;
1271         default:
1272                 return -EINVAL;
1273         }
1274         if (syscall_nr < 0)
1275                 return -ENOENT;
1276
1277         switch (entryexit) {
1278         case LTTNG_SYSCALL_ENTRY:
1279                 switch (abi) {
1280                 case LTTNG_SYSCALL_ABI_NATIVE:
1281                         bitmap = filter->sc_entry;
1282                         break;
1283                 case LTTNG_SYSCALL_ABI_COMPAT:
1284                         bitmap = filter->sc_compat_entry;
1285                         break;
1286                 default:
1287                         return -EINVAL;
1288                 }
1289                 break;
1290         case LTTNG_SYSCALL_EXIT:
1291                 switch (abi) {
1292                 case LTTNG_SYSCALL_ABI_NATIVE:
1293                         bitmap = filter->sc_exit;
1294                         break;
1295                 case LTTNG_SYSCALL_ABI_COMPAT:
1296                         bitmap = filter->sc_compat_exit;
1297                         break;
1298                 default:
1299                         return -EINVAL;
1300                 }
1301                 break;
1302         default:
1303                 return -EINVAL;
1304         }
1305         if (!test_bit(syscall_nr, bitmap))
1306                 return -EEXIST;
1307         bitmap_clear(bitmap, syscall_nr, 1);
1308
1309         return 0;
1310 }
1311
1312 int lttng_syscall_filter_disable_event(struct lttng_kernel_event_common *event)
1313 {
1314         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_event(event);
1315         int ret;
1316
1317         ret = lttng_syscall_filter_disable(syscall_table->sc_filter,
1318                 event->priv->desc->event_name, event->priv->u.syscall.abi,
1319                 event->priv->u.syscall.entryexit);
1320         if (ret)
1321                 return ret;
1322
1323         switch (event->type) {
1324         case LTTNG_KERNEL_EVENT_TYPE_RECORDER:
1325                 break;
1326         case LTTNG_KERNEL_EVENT_TYPE_NOTIFIER:
1327         {
1328                 hlist_del_rcu(&event->priv->u.syscall.node);
1329                 break;
1330         }
1331         default:
1332                 WARN_ON_ONCE(1);
1333                 return -ENOSYS;
1334         }
1335         return 0;
1336 }
1337
1338 void lttng_syscall_table_set_wildcard_all(struct lttng_event_enabler_common *event_enabler)
1339 {
1340         struct lttng_kernel_syscall_table *syscall_table = get_syscall_table_from_enabler(event_enabler);
1341         enum lttng_kernel_abi_syscall_entryexit entryexit;
1342         int enabled = event_enabler->enabled;
1343
1344         if (event_enabler->event_param.instrumentation != LTTNG_KERNEL_ABI_SYSCALL)
1345                 return;
1346         if (event_enabler->event_param.u.syscall.abi != LTTNG_KERNEL_ABI_SYSCALL_ABI_ALL)
1347                 return;
1348         if (event_enabler->event_param.u.syscall.match != LTTNG_KERNEL_ABI_SYSCALL_MATCH_NAME)
1349                 return;
1350         if (strcmp(event_enabler->event_param.name, "*"))
1351                 return;
1352
1353         entryexit = event_enabler->event_param.u.syscall.entryexit;
1354         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRY || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1355                 WRITE_ONCE(syscall_table->syscall_all_entry, enabled);
1356
1357         if (entryexit == LTTNG_KERNEL_ABI_SYSCALL_EXIT || entryexit == LTTNG_KERNEL_ABI_SYSCALL_ENTRYEXIT)
1358                 WRITE_ONCE(syscall_table->syscall_all_exit, enabled);
1359 }
1360
1361 static
1362 const struct trace_syscall_entry *syscall_list_get_entry(loff_t *pos)
1363 {
1364         const struct trace_syscall_entry *entry;
1365         int iter = 0;
1366
1367         for (entry = sc_table.table;
1368                         entry < sc_table.table + sc_table.len;
1369                          entry++) {
1370                 if (iter++ >= *pos)
1371                         return entry;
1372         }
1373         for (entry = compat_sc_table.table;
1374                         entry < compat_sc_table.table + compat_sc_table.len;
1375                          entry++) {
1376                 if (iter++ >= *pos)
1377                         return entry;
1378         }
1379         /* End of list */
1380         return NULL;
1381 }
1382
1383 static
1384 void *syscall_list_start(struct seq_file *m, loff_t *pos)
1385 {
1386         return (void *) syscall_list_get_entry(pos);
1387 }
1388
1389 static
1390 void *syscall_list_next(struct seq_file *m, void *p, loff_t *ppos)
1391 {
1392         (*ppos)++;
1393         return (void *) syscall_list_get_entry(ppos);
1394 }
1395
1396 static
1397 void syscall_list_stop(struct seq_file *m, void *p)
1398 {
1399 }
1400
1401 static
1402 int get_sc_table(const struct trace_syscall_entry *entry,
1403                 const struct trace_syscall_entry **table,
1404                 unsigned int *bitness)
1405 {
1406         if (entry >= sc_table.table && entry < sc_table.table + sc_table.len) {
1407                 if (bitness)
1408                         *bitness = BITS_PER_LONG;
1409                 if (table)
1410                         *table = sc_table.table;
1411                 return 0;
1412         }
1413         if (!(entry >= compat_sc_table.table
1414                         && entry < compat_sc_table.table + compat_sc_table.len)) {
1415                 return -EINVAL;
1416         }
1417         if (bitness)
1418                 *bitness = 32;
1419         if (table)
1420                 *table = compat_sc_table.table;
1421         return 0;
1422 }
1423
1424 static
1425 int syscall_list_show(struct seq_file *m, void *p)
1426 {
1427         const struct trace_syscall_entry *table, *entry = p;
1428         unsigned int bitness;
1429         unsigned long index;
1430         int ret;
1431         const char *name;
1432
1433         ret = get_sc_table(entry, &table, &bitness);
1434         if (ret)
1435                 return ret;
1436         if (!entry->desc)
1437                 return 0;
1438         if (table == sc_table.table) {
1439                 index = entry - table;
1440                 name = &entry->desc->event_name[strlen(SYSCALL_ENTRY_STR)];
1441         } else {
1442                 index = (entry - table) + sc_table.len;
1443                 name = &entry->desc->event_name[strlen(COMPAT_SYSCALL_ENTRY_STR)];
1444         }
1445         seq_printf(m,   "syscall { index = %lu; name = %s; bitness = %u; };\n",
1446                 index, name, bitness);
1447         return 0;
1448 }
1449
1450 static
1451 const struct seq_operations lttng_syscall_list_seq_ops = {
1452         .start = syscall_list_start,
1453         .next = syscall_list_next,
1454         .stop = syscall_list_stop,
1455         .show = syscall_list_show,
1456 };
1457
1458 static
1459 int lttng_syscall_list_open(struct inode *inode, struct file *file)
1460 {
1461         return seq_open(file, &lttng_syscall_list_seq_ops);
1462 }
1463
1464 const struct file_operations lttng_syscall_list_fops = {
1465         .owner = THIS_MODULE,
1466         .open = lttng_syscall_list_open,
1467         .read = seq_read,
1468         .llseek = seq_lseek,
1469         .release = seq_release,
1470 };
1471
1472 /*
1473  * A syscall is enabled if it is traced for either entry or exit.
1474  */
1475 long lttng_syscall_table_get_active_mask(struct lttng_kernel_syscall_table *syscall_table,
1476                 struct lttng_kernel_abi_syscall_mask __user *usyscall_mask)
1477 {
1478         uint32_t len, sc_tables_len, bitmask_len;
1479         int ret = 0, bit;
1480         char *tmp_mask;
1481         struct lttng_syscall_filter *filter;
1482
1483         ret = get_user(len, &usyscall_mask->len);
1484         if (ret)
1485                 return ret;
1486         sc_tables_len = get_sc_tables_len();
1487         bitmask_len = ALIGN(sc_tables_len, 8) >> 3;
1488         if (len < sc_tables_len) {
1489                 return put_user(sc_tables_len, &usyscall_mask->len);
1490         }
1491         /* Array is large enough, we can copy array to user-space. */
1492         tmp_mask = kzalloc(bitmask_len, GFP_KERNEL);
1493         if (!tmp_mask)
1494                 return -ENOMEM;
1495         filter = syscall_table->sc_filter;
1496
1497         for (bit = 0; bit < sc_table.len; bit++) {
1498                 char state;
1499
1500                 if (syscall_table->syscall_dispatch) {
1501                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1502                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1503                                 state = test_bit(bit, filter->sc_entry)
1504                                         || test_bit(bit, filter->sc_exit);
1505                         else
1506                                 state = 1;
1507                 } else {
1508                         state = 0;
1509                 }
1510                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1511         }
1512         for (; bit < sc_tables_len; bit++) {
1513                 char state;
1514
1515                 if (syscall_table->compat_syscall_dispatch) {
1516                         if (!(READ_ONCE(syscall_table->syscall_all_entry)
1517                                         || READ_ONCE(syscall_table->syscall_all_exit)) && filter)
1518                                 state = test_bit(bit - sc_table.len,
1519                                                 filter->sc_compat_entry)
1520                                         || test_bit(bit - sc_table.len,
1521                                                 filter->sc_compat_exit);
1522                         else
1523                                 state = 1;
1524                 } else {
1525                         state = 0;
1526                 }
1527                 bt_bitfield_write_be(tmp_mask, char, bit, 1, state);
1528         }
1529         if (copy_to_user(usyscall_mask->mask, tmp_mask, bitmask_len))
1530                 ret = -EFAULT;
1531         kfree(tmp_mask);
1532         return ret;
1533 }
1534
1535 int lttng_abi_syscall_list(void)
1536 {
1537         struct file *syscall_list_file;
1538         int file_fd, ret;
1539
1540         file_fd = lttng_get_unused_fd();
1541         if (file_fd < 0) {
1542                 ret = file_fd;
1543                 goto fd_error;
1544         }
1545
1546         syscall_list_file = anon_inode_getfile("[lttng_syscall_list]",
1547                                           &lttng_syscall_list_fops,
1548                                           NULL, O_RDWR);
1549         if (IS_ERR(syscall_list_file)) {
1550                 ret = PTR_ERR(syscall_list_file);
1551                 goto file_error;
1552         }
1553         ret = lttng_syscall_list_fops.open(NULL, syscall_list_file);
1554         if (ret < 0)
1555                 goto open_error;
1556         fd_install(file_fd, syscall_list_file);
1557         return file_fd;
1558
1559 open_error:
1560         fput(syscall_list_file);
1561 file_error:
1562         put_unused_fd(file_fd);
1563 fd_error:
1564         return ret;
1565 }